It is known in the art to form a cooled mirror for a high power laser by combining a rigid substrate with a faceplate having a number of channels through which coolant is flowed during the system operation. Conventionally, the faceplate is attached to the substrate by brazing, a high temperature process which tends to introduce distortions in the optical faceplate and to leave residual stresses in the finished mirror. Copending U.S. patent application Ser. No. 251,680 by John Bluege illustrates the attachment of a faceplate to a substrate by use of chemical vapor deposition to form a bond between the two pieces, thus reducing the amount of stress because chemical vapor deposition is a lower temperature process than brazing. U.S. Pat. No. 4,133,369 issued to Maire et al illustrates the fabrication of a conventional heat exchanger by a variety of plating methods including chemical deposition.